(1) Field of the Invention
The present invention relates to a breaker apparatus and breaker unit suitably applicable to a power distributing apparatus for use in communication systems.
(2) Description of the Related Art
In a terminal station of a communication system, a breaker apparatus is provided in a power distributing apparatus which is for the purpose of distributing power, fed through a power-supply line, to each of units in that station. The breaker apparatus is made up of a breaker (NFB: Non Fuse Breaker) which serves as a current limiter for, when a current exceeding a predetermined value flows, breaking that current, with a current supplied being made to be fed through the NFB to each of the units so that the supply of an excessive current exceeding an allowable value of each of the units thereto is preventable.
Meanwhile, for coping with a system extension in the future, a communication system is usually designed in consideration of the enlargement of an exchange system associated with the extension of that communication system. Accordingly, in a power distributing apparatus including such a prior breaker apparatus, the power-supply ability per one rack column is determined on the basis of the maximum number of racks or units in the station, and the power distributing apparatus is designed and manufactured to exhibit the maximum power-supply ability.
In addition, the communication system is requested to execute the maintenance without its stopping, and therefore, employs a double-powered construction.
There are a CG (Communication Ground) forming a return ground for a power supply, a SG (Signal Ground) being a ground for a signal, and an FG (Frame Ground) for human-body protection among the kinds of grounding for a communication system,. Further, the ground systems are classified into an isolated ground system and an integrated ground system, and in the case of communication systems installed overseas, either the isolated ground system or the integrated ground system is taken according to the standard the nation concerned employs.
The isolated ground system is principally employed in Japan, European nations and other countries, and in this system, all the ground earths are gathered at a GW (Ground Window) in a station house and then connected to a main ground at one point (see FIG. 3). Thus, since the isolated ground system takes a structure in which the FGs are connected at one point, an advantage exists in that, even if that building is struck by thunderbolt or the like, it is difficult that the noises caused by the thunderbolt or the like are introduced through the FGs into the system, whereas there is a disadvantage in that the ground lines are led from the communication system to a power room of each of the units to cause a higher wiring cost.
The integrated ground system is principally employed in the United States of America and others, and each of the grounds within the communication system is connected to a CG within a power distributing apparatus (see FIG. 16) which in turn, is connected to an FG of an exchange system. Further, the CG in the power distributing apparatus is connected as a power supply return in the power room to a rectifier.
This integrated ground system does not require the leading of the SG from the communication system to the external but requires only a connection of the FG of the power distributing apparatus to a neighboring FG of, for example, an exchange system, and therefore, the ground line wiring work is facilitated to decrease the wiring work cost, and the requirement to the electric insulation of the communication system from the station house building does not necessarily exist, and hence, a spanning cable rack or the like of the communication system is not needed to be electrically insulated from the station house constructing materials, which facilitates the associated works and lowers the wiring work cost, so that its construction cost becomes lower than that of the aforesaid isolated ground system. However, when being used for a large-scale communication system, this integrated ground system shows a disadvantage of being poor at noises because, at the falling of a thunderbolt, the thunderbolt noises are introduced through a shield for signal cables existing between spanning rows into the building.
The selection between the isolated ground system and the integrated ground system depends upon the standard ruled by the nation employing the communication system, and the ground system meeting the standard by that nation is chosen, whereupon a power distributing apparatus and a communication system are produced accordingly.
In the case of a power distributing apparatus equipped with such a prior breaker apparatus, since difficulty is experienced to perform the extension of the NFB or the like resulting from the enlargement of the power-supply capacity, as mentioned before, in the design of the power distributing apparatus, in consideration of the future extension of the exchange system or the like, the power-supply ability per one rack column, and in its turn the breaker capacity, is designed on the basis of the maximum number of racks in the station.
Accordingly, the power distributing apparatus with the prior breaker apparatus is constructed to provide a breaker capacity corresponding to the maximum power-supply ability at all the time, with the result that the manufacturing cost of the power distributing apparatus increases. Further, in a small-scale communication system (small station system), the rate of the cost of the power distributing apparatus to the total system cost rises, and the rise of the power distributing apparatus cost hinders lowering the total system cost, thus reducing the cost advantage on the market when being applied to a small station system.
Furthermore, in the recent years, with the improvement of the functions of the units constituting a communication system, its densification advances, with the result that the power consumption increases in units of units or in units of racks, and hence, since a consideration should be given to a power-supply ability covering this increasing power consumption at the above-mentioned design of the power distributing apparatus, the power-supply capacity of the power distributing apparatus further increases to further heighten the manufacturing cost of the power distributing apparatus.
Still further, although the communication system is required to undergo maintenance without stopping and, hence, its power supply system employs a double-powered construction, in the case of a power distributing apparatus equipped with a prior breaker unit, the replacement of the NFB or the extension of the power distributing apparatus requires that the power supply to the distribution board to be replaced is turned off or that the work for the replacement or the extension is done risking the short-circuit accident in the hot-line condition without turning off the power supply, which creates a problem in the stabilization of the system operation.
Besides, since the NFB is attached through screws to the power distributing apparatus, there is a problem in that the replacement work efficiency of the NFB deteriorates.
Moreover, because the determination as to whether the ground system is constructed as the isolated ground system or as the integrated ground system relies upon the standard taken by the nation installing the communication system and the power distributing apparatus is to be manufactured to be conformable to that nation, there is a problem in that difficulty is encountered to commonly use the products, which causes the increase in the number of parts so that the manufacturing cost goes up.
The present invention has been developed with a view to eliminating the above-mentioned problems, and it is therefore an object of this invention to provide the improvement of constructions of a breaker apparatus and breaker unit which is capable of not only constituting a power distributing apparatus with a necessary but minimized construction along with extending breaker units in the minimum unit as needed, but also commonly using parts irrespective of the change of the ground system, and even allowing the replacement work in the hot-line condition without the suspension of the power supply to the system.
For these purposes, in accordance with this invention, there is provided a breaker apparatus comprising a breaker unit including a breaker part for supplying/cutting off power, a power connecting part for connecting the breaker part to a power line, a first unit connecting part for supplying power through the breaker part to a unit side, a ground connecting part to be connected to a ground line, and a second unit connecting part for connecting the unit side through the ground connecting part to the ground line, and further comprising a breaker unit mounting board including a mating power connecting part on which the power connecting part is detachably mountable, with the mating power connecting part connecting the power connecting part to the power line when the power connecting part is mounted thereon, a mating ground connecting part on which the ground connecting part is detachably mountable, with the mating ground connecting part connecting the ground connecting part to the ground line when the ground connecting part is mounted thereon, a first connection mediating part allowed to connect a power supply line to the unit side and the first unit connecting part and a second connection mediating part allowed to connect a ground line to the unit side to the second unit connecting part.
Thus, owing to the breaker apparatus according to this invention, a power distributing apparatus can be constructed through the use of a breaker unit with a necessary but minimized power capacity and, hence, can be manufactured at a minimum cost, thus reducing the system manufacturing cost. In addition, particularly, in constructing a small station system, the useless initial investment is reducible and the rate of the cost of the power distributing apparatus to the total manufacturing cost is lowered.
In this case, it is also acceptable that the breaker unit is equipped with a board member on which disposed are the aforesaid breaker part, power connecting part, first unit connecting part, ground connecting part and second unit connecting part, and the board member is provided with a first connecting line for connecting the breaker part to the power connecting part, a second connecting line for connecting the breaker part to the first unit connecting part and a third connecting line for connecting the ground connecting part to the second unit connecting part.
Accordingly, the above-described breaker apparatus according to this invention can achieve the size-reduction of the breaker unit to construct the breaker unit as a small-sized unit, and can easily produce the power distributing apparatus in accordance with a required power capacity, and further, facilitate the replacement of the breaker unit at the system maintenance, the enlargement of the breaker unit and other operations to enhance the working efficiency.
In addition, it is also possible that the aforesaid power connecting part is made up of a power connecting piece member having a piece portion and a leg portion constructed such that at least their surface portions serve as electric conducting portions, and a first connecting part electrically connected to the leg portions of the power connecting piece member is formed in the first connecting line.
With this construction, the breaker apparatus according to this invention allows the power connecting piece member to be easily connected to the first connecting line, which simplifies the construction of the breaker unit and reduces the manufacturing cost.
Furthermore, it is also appropriate that the foregoing first connecting part is provided with a plurality of connecting portions arranged at a predetermined interval along a portion facing the mating power connecting part so that the first connecting part is electrically connectable to the leg portions of the power connecting piece member.
With this construction, the breaker apparatus according to this invention can increase and decrease the number of the power connecting piece members, with the result that the useless initial investment is held down while the manufacturing cost is cut down.
Besides, it is also possible to place a holder for connecting the adjacent power connecting piece members to each other.
Thus, in the breaker apparatus according to this invention, the power connecting piece members are preventable from falling down, and hence, the electrical connection between the power connecting piece members and the mating power connecting part is surely maintainable, thereby improving the reliability of the device.
Still further, it is also appropriate that the foregoing first connecting part is equipped with a plurality of connecting portions arranged at a predetermined interval along a direction crossing a portion facing the mating power connecting part to be electrically connectable to the leg portions of the power connecting piece members.
As a result of this construction, in the breaker apparatus according to this invention, the power connecting piece members in the first connecting part can be disposed at a desired position.
Moreover, it is also acceptable that the aforesaid ground connecting part is made up of a ground connecting piece member having a piece portion and a leg portion constructed such that at least their surface portions serve as electric conductive portions, and a second connecting part electrically connected to the leg portions of the ground connecting piece members is formed in the third connecting line.
Whereupon, the breaker apparatus according to this invention can simplify the construction of the breaker unit and reduce its manufacturing cost.
Furthermore, it is also acceptable that the aforesaid second connecting part is equipped with a plurality of connecting portions arranged at a predetermined interval along a portion facing the mating ground connecting part so that it is electrically connectable to the leg portions of the plurality of ground connecting piece members.
Thereupon, in the breaker apparatus according to this invention, the number of the ground connecting piece members can be increased and decreased when necessary, and the useless initial investment can be held down while the manufacturing cost can be cut down.
Besides, it is also possible to place a holder for mutually connecting the adjacent ground connecting piece members.
Accordingly, in the breaker apparatus according to this invention, the ground connecting piece members are preventable from falling down, and hence, the electrical connection between the ground connecting piece members and the mating ground connecting part is surely maintainable, thereby improving the reliability of the device.
Still further, it is also appropriate that the aforesaid second connecting part is equipped with a plurality of connecting portions arranged at a predetermined interval along a direction crossing a portion facing the mating ground connecting part to be electrically connectable to the leg portions of the ground connecting piece members.
Accordingly, in the breaker apparatus according to this invention, the ground connecting piece members in the second connecting part can be disposed at a desired position.
Still further, it is also appropriate that, at the mounting of the breaker unit on the breaker unit mounting board, the connection between the ground connecting part and the mating ground connecting part is done prior to the connection between the power connecting part and the mating power connecting part, while at the detachment of the breaker unit from the breaker unit mounting board, releasing the ground connecting part and the mating ground connecting part from their connection is made after releasing the power connecting part and the mating power connecting part from their connection.
Thereupon, in the breaker apparatus according to this invention, in the attachment/detachment of the breaker unit to/from the breaker unit mounting board, the connection between the ground connecting part and the mating ground connecting part is always established at the connection between the power connecting part and the mating power connecting part and the releasing from this connection, and therefore, even when the breaker unit is attached/detached to/from the breaker unit mounting board in the hot-line condition, the earth line is securable, thus improving the safety.
Besides, the aforesaid first and second unit connecting parts can also be mounted on a common first connector part, whereupon, in the breaker apparatus according to this invention, the wiring becomes simple to reduce the manufacturing cost, and the working efficiency of the attachment/detachment of the breaker unit to/from the breaker unit mounting board is improvable.
Moreover, it is also appropriate that the breaker unit mounting board is composed of an insulating plate member, a first conductive plate member mounted on one surface of the insulating plate member to constitute the mating power connecting part, a power line connecting part provided on the other surface of the insulating plate member to be used for the power line, a second conductive plate member mounted on the one surface of the insulating plate member to organize the mating ground connecting part, and a ground line connecting part provided on the other surface of the insulating plate member to be used for the ground line.
With this construction, in the breaker apparatus according to this invention, the breaker unit mounting board can be made with a simple construction so that the manufacturing cost is reducible, and further, the breaker unit mounting board can be constructed to have a small dimension so that the size reduction of the device is achievable.
Besides, the mating power connecting part can also have an engaging hole portion accommodating the power connecting piece member and electrically connected to the power line.
Thus, in the breaker apparatus according to this invention, the easy connection between the power connecting piece member and the power line and the releasing thereof from the connection become feasible, thereby enhancing the working efficiency.
In addition, the mating ground connecting part can also have engaging hole portions accommodating the ground connecting piece members and electrically connected to the ground line.
Thus, in the breaker apparatus according to this invention, the easy connection between the ground connecting piece members and the ground line and the releasing thereof from the connection become feasible, thereby enhancing the working efficiency.
Furthermore, it is also appropriate that a connecting portion to the power supply line extending toward the unit side and a connecting portion to the ground line extending toward the unit side are mounted on a common second connector part while the second connector part and the first connector part are made to be connectable to each other.
With this structure, in the breaker apparatus according to this invention, the wiring becomes simple and the manufacturing cost is reducible, besides the working efficiency of the attachment/detachment of the breaker unit to/from the breaker unit mounting board is improvable.
Still further, it is also acceptable that the aforesaid first and second connection mediating parts are constructed as a connector through-hole for enabling the first and second connector parts to be connected to each other.
Accordingly, in the breaker apparatus according to this invention, the wiring becomes simple and the manufacturing cost is reducible, and further, the working efficiency of the attachment/detachment of the breaker unit to/from the breaker unit mounting board is improvable, besides the construction of the breaker unit mounting board can be simplified and the manufacturing cost can be cut down.
In addition, the ground connecting part can also be constructed as a ground connecting part to be connected to one kind of ground line, and therefore, the breaker apparatus according to this invention contributes to an easy arrangement of an isolated ground system and further to the reduction of the manufacturing cost.
Besides, the ground connecting part can also be constructed as a ground connection part to be connected to a plurality of kinds of ground lines, and therefore, the breaker apparatus according to this invention contributes to an easy arrangement of an integrated ground system and further to the reduction of the manufacturing cost.
Moreover, the ground connecting part can also be equipped with a ground fixed connection portion to be fixedly connected to one type of ground line, and a connecting switch portion allowed to connect the ground fixed connection portion to a different type of ground line. Therefore, in the breaker apparatus according to this invention, the one type of ground line and the different type of ground line can share the breaker unit, thereby lowering the manufacturing cost.
Furthermore, the breaker part can also be made as a non-fuse breaker, and hence, with the breaker apparatus according to this invention, the operations/practical use of the breaker unit become easy and the running cost comes down.
In addition, in accordance with this invention, there is provided a breaker apparatus comprising a breaker unit including a non-fuse breaker part for supplying and cutting off power, a power connecting part composed of a power connecting piece member having a piece portion and a leg portion formed such that at least their surface portions serve as conductive portions for connecting the non-fuse breaker part to a power line, a ground connecting part composed of a ground connecting piece member having a piece portion and a leg portion formed so that at least their surface portions serve as conductive portions for connection with a ground line, a unit connecting part for supplying power through the non-fuse breaker part to a unit side and further for connecting the unit side through the ground connecting part to the ground line, and a substrate or board member for holding the breaker part, the power connecting part, the ground connecting part and the unit connecting part, and for carrying a fourth connecting line having a first engaging section for making a connection between the non-fuse breaker part and the power connecting part and allowed to engage with the leg portion of the power connecting piece member and a fifth connecting line for making a connection between the non-fuse breaker part and the unit connecting part and a connection between the ground connecting part and the unit connecting part, and further, comprising a breaker unit mounting board, in correspondence with each of the plurality of breaker units, including a mating power connecting part having an engaging hole portion allowed to engage with the power connecting piece member and electrically connected to the power line for allowing detachable mounting of the power connecting part and for connecting the power connecting part to the power line when the power connecting part is mounted on the mating power connecting part, a mating ground connecting part having an engaging hole portion allowed to engage with the ground connecting piece member and electrically connected to the ground line for allowing detachable mounting of the ground connecting part and for connecting the ground connecting part to the ground line when the ground connecting part is mounted on the mating ground connecting part, and a connection mediating part for making a connection between a power supply line extending toward the unit side and the unit connecting part and for making a connection between a ground line to the unit side and the unit connecting part.
Thus, the above-mentioned breaker apparatus according to this invention can provide the following advantages.
(1) Since a power distributing apparatus can be constructed with breaker units each having a necessary but minimized power capacity, the power distributing apparatus is producible at a minimum cost and the system manufacturing cost is reducible. In addition, particularly, in constructing a small station system, the useless initial investment is held down and the rate of the cost of the power distributing apparatus to the total manufacturing cost is lowered. Further, the size reduction of the breaker unit is achievable and the breaker unit can be constructed as a small-sized unit and the power distributing apparatus can easily be constructed to a required power capacity. Still further, the replacement of the breaker unit at the maintenance of the system or the like, the extension of the breaker unit and others are facilitated to enhance the working efficiency.
(2) The construction of the breaker unit is simple, so that the manufacturing cost is reducible.
(3) The connection and release from the connection between the power connecting piece member and the power line is easy, thus improving the working efficiency.
(4) The connection and release from the connection between the ground connecting piece member and the ground line is easy, thus improving the working efficiency.
(5) The operations/practical use of the breaker unit become simple, and the running cost is reducible.
Moreover, in accordance with this invention, there is provided a breaker unit comprising a breaker part for supplying and cutting off power, a power connecting part for connecting the breaker part to a power line, a first unit connecting part for supplying power through the breaker part to a unit side, a ground connecting part to be connected to a ground line, and a second unit connecting part for connecting the unit side through the ground connecting part to the ground line.
Accordingly, the breaker unit according to this invention can constitute a power distributing apparatus in a state of having a necessary but minimum power capacity, and hence, contributes to the manufacturing of the power distributing apparatus at the minimum cost and consequently cuts down the system manufacturing cost. In addition, in constructing a small station system, the useless initial investment is held down and the rate of the cost of the power distributing apparatus to the total manufacturing cost comes down.